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121.
Angelina Sarapulova Daria Mikhailova Ljubomira Ana Schmitt Steffen Oswald Natalia Bramnik Helmut Ehrenberg 《Journal of Sol-Gel Science and Technology》2012,62(1):98-110
LiCoPO4-coated disordered carbon nanofibers (CNFs/LiCoPO4) were obtained by a sol–gel method, using triethyl phosphite or triethyl phosphate as the phosphorous source. The crystal
structure of the products was analyzed by X-ray powder diffraction, while morphology was studied using scanning electron microscopy,
transmission electron microscopy, Auger electron spectroscopy and X-ray photoelectron spectroscopy. Optimal synthesis conditions
for the CNFs/LiCoPO4 in light of the best electrochemical performance are discussed. The best discharge capacity 105 mAh/g (or ca. 63% of the
theoretical capacity) shows the material with 40% CNFs/LiCoPO4 and addition coating by carbon black. This composition has a best purity of active materials and point coverage of CNFs.
The X-ray photoelectron C1s spectra of the CNFs surface without and with sputter erosion show enhancement of C–O bonds at
the fiber surface, which does not influence significantly electrochemical behavior of the composite materials. 相似文献
122.
Complexes of type C6H7(+)·L (L = N2 and CO2) studied by explicitly correlated coupled cluster theory
Complexes of the benzenium ion (C(6)H(7)(+)) with N(2) or CO(2) have been studied by explicitly correlated coupled cluster theory at the CCSD(T)-F12x (x = a, b) level [T. B. Adler et al., J. Chem. Phys. 127, 221106 (2007)] and the double-hybrid density functional B2PLYP-D [T. Schwabe and S. Grimme, Phys. Chem. Chem. Phys. 9, 3397 (2007)]. Improved harmonic vibrational wavenumbers for C(6)H(7)(+) have been obtained by CCSD(T?)-F12a calculations with the VTZ-F12 basis set. Combining them with previous B2PLYP-D anharmonic contributions we arrive at anharmonic wavenumbers which are in excellent agreement with recent experimental data from p-H(2) matrix isolation IR spectroscopy [M. Bahou et al., J. Chem. Phys. 136, 154304 (2012)]. The energetically most favourable conformer of C(6)H(7)(+)·N(2) shows a π-bonded structure similar to C(6)H(7)(+)·Rg (Rg = Ne, Ar) [P. Botschwina and R. Oswald, J. Phys. Chem. A 115, 13664 (2011)] with D(e) ≈ 870 cm(-1). For C(6)H(7)(+)·CO(2), a slightly lower energy is calculated for a conformer with the CO(2) ligand lying in the ring-plane of the C(6)H(7)(+) moiety (D(e) ≈ 1508 cm(-1)). It may be discriminated from other conformers through a strong band predicted at 1218 cm(-1), red-shifted by 21 cm(-1) from the corresponding band of free C(6)H(7)(+). 相似文献
123.
P. Oswald 《Numerical Algorithms》2001,27(2):131-152
The connection between the multilevel factorization method recently proposed by Sarin and Sameh for solving mixed discretizations of the Stokes equation using a divergence-free finite element formulation, and hierarchical basis preconditioners for the Poisson problem is established. For the 2D triangular Taylor–Hood element, a preconditioner is proposed that could be useful in fractional step methods. 相似文献
124.
125.
126.
Reactively sputtered Ta-Si-Nx barrier systems of different nitrogen content on copper were investigated by photoelectron spectroscopy (XPS, UPS) and scanning tunnelling microscopy (STM). The measured photoelectron spectra (excitation He-I) showed a clear dependence of the electron state density near the Fermi edge on the content of nitrogen. These results correlate with the I(U) characteristics of the STM measurements and the electrical conductivity of these layers. 相似文献
127.
128.
P. Oswald 《Numerische Mathematik》2008,111(2):267-291
We prove the optimality of hierarchical and BPX-type preconditioners for finite element discretizations with nonconforming P1 finite elements. Such preconditioners were proposed about 15 years ago, and until now only suboptimal estimates of their preconditioning properties have been available. The main new tool is an improved Bernstein type inequality for an associated subdivision process generated by the prolongations which allows us to give an asymptotically optimal upper bound for the spectrum of the preconditioned systems. 相似文献
129.
N. A. Rzakuliev V. M. Konnov V. N. Yakimkin V. V. Ushakov A. A. Gippius J. Oswald J. Pastrňák 《Czechoslovak Journal of Physics》1988,38(11):1288-1293
New experimental data on luminescence spectra of Pr and Nd ions implanted into GaAs and GaP crystals and the results on luminescence kinetics of Nd doped GaP are presented. The results show that RE ions form different complexes in measured samples. 相似文献
130.
(MDS)- and Laguerre codes are closely related to geometry and can be used in order to construct certain finite incidence structures. Here we present some structure theorems on near rings, introduce the notion of a coding set of a near ring, which enables us to construct (MDS)-codes, and discuss the same problem for Laguerre codes. To find non trivial Laguerre sets in a near ring is much more difficult.Dedicated to Giuseppe Tallini on the occasion of his 60 th birthday 相似文献